//: concurrency/waxomatic/WaxOMatic.java
// Basic task cooperation.
package concurrency.waxomatic;

import java.util.concurrent.*;

import static net.mindview.util.Print.*;

class Car
{
    private boolean waxOn = false;
    
    public synchronized void waxed()
    {
        waxOn = true; // Ready to buff
        notifyAll();
    }
    
    public synchronized void buffed()
    {
        waxOn = false; // Ready for another coat of wax
        notifyAll();
    }
    
    public synchronized void waitForWaxing()
        throws InterruptedException
    {
        while (waxOn == false)
            wait();
    }
    
    public synchronized void waitForBuffing()
        throws InterruptedException
    {
        while (waxOn == true)
            wait();
    }
}

class WaxOn implements Runnable
{
    private Car car;
    
    public WaxOn(Car c)
    {
        car = c;
    }
    
    public void run()
    {
        try
        {
            while (!Thread.interrupted())
            {
                printnb("Wax On! ");
                TimeUnit.MILLISECONDS.sleep(200);
                car.waxed();
                car.waitForBuffing();
            }
        }
        catch (InterruptedException e)
        {
            print("Exiting via interrupt");
        }
        print("Ending Wax On task");
    }
}

class WaxOff implements Runnable
{
    private Car car;
    
    public WaxOff(Car c)
    {
        car = c;
    }
    
    public void run()
    {
        try
        {
            while (!Thread.interrupted())
            {
                car.waitForWaxing();
                printnb("Wax Off! ");
                TimeUnit.MILLISECONDS.sleep(200);
                car.buffed();
            }
        }
        catch (InterruptedException e)
        {
            print("Exiting via interrupt");
        }
        print("Ending Wax Off task");
    }
}

public class WaxOMatic
{
    public static void main(String[] args)
        throws Exception
    {
        Car car = new Car();
        ExecutorService exec = Executors.newCachedThreadPool();
        exec.execute(new WaxOff(car));
        exec.execute(new WaxOn(car));
        TimeUnit.SECONDS.sleep(5); // Run for a while...
        exec.shutdownNow(); // Interrupt all tasks
    }
} /*
   * Output: (95% match) Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On!
   * Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax On! Wax Off! Wax
   * On! Exiting via interrupt Ending Wax On task Exiting via interrupt Ending Wax Off task
   */// :~
